The present invention relates to internal cooling within a gas turbine engine, and more particularly, to seals used between combustor components that also enhance cooling within the region of the seal.
Air management is an important consideration in combustor design. Air streams provide an oxidizer for the combustion process and also provide cooling to hot gas path components of the combustor. Seals are typically provided between various components of the combustor to prevent hot combustion gas from leaking from the combustor. Seal configurations and functions of those seals are unique in the combustor. For example, a seal providing complete sealing of flow from one area to another may not be desired but rather, a seal resulting in a small amount of cooling air “leak” may be preferred. Within combustion zones, cooling must be properly designed to provide adequate cooling for hot gas path components while only minimally disturbing combustion ignition and stability.
Seals are typically used between, for example, gas turbine combustor liners and transition pieces or ducts that carry hot combustion gases to the first stage of the gas turbine. They typically include C-rings, spring-finger or “hula” rings, cloth seals and the like, all of which are subjected to high temperature and pressure as well as high gradients of pressure and temperature across the seals.
There remains need for enhanced levels of active cooling with minimal pressure losses at high-firing temperatures by, for example, targeting hot streaks along the hot side of the combustor liner and transition piece or duct for preferential cooling.